Apparatus for the application of a refractory lining to the inside wall of metallurgical vessels, as well as a moulding unit to be utilized in combination therewith

ABSTRACT

The apparatus comprises a sand slinging device for applying refractory lining in granular form, a molding unit temporarily installed in and spaced from the vessel walls, and means for freeing the mold from the installed lining comprising vibration generators distributed around the inner periphery of the mold and hydraulic jacks, preferably removable, distributed about such periphery neat the bottom of the mold and expandable downwardly to raise the mold. A set of three jacks and a set of three vibrators are preferred, attached respectively to the lower and upper parts of a two-part mold. The preferred form also has manually operable jacks and centering spindles for the mold and at its bottom edges a cylindrical ring movable to sealingly engage the surface therebelow, an annular platform proximate to the top of the lower part of the mold, and vibration generators comprising eccentric masses rotatable about vertical axis in different directions of rotation. In the method, the lower part of the mold is positioned, raised free of the bottom of the vessel and centered and levelled by the manual jacks, with the ring resting on the vessel bottom; the platform and upper part of the mold are assembled on the lower part, the centering spindles are retracted; the refractory mass is slung into the space between the mold and the vessel walls; the hydraulic jacks are positioned at operative heights; the vibration generators and hydraulic jacks are operated and then stopped; the manual jacks are adjusted and the hydraulic jacks preferably removed and then the remaining mold parts. Concurrent and separate controls for the hydraulic jacks are preferably provided.

United States Patent 1 Dekker et al.

Inventors: Cornelis Dekker, ljmuiden; Pieter Karel Joustra; Josephus Paro, both of Heemskerk, all of Netherlands Assignee: Koninklijke .Nederlandsche Hoogovens en Staalfabrieken N.V., Ijmuiden, Netherlands Filed: June 14, 1971 Appl. No.: 152,668

[ 1 Feb. 13, 1973 [S7 ABSTRACT The apparatus comprises a sand slinging device for applying refractory lining in granular form, a molding unit temporarily installed in and spaced from the vessel walls, and means for freeing the mold from the installed lining comprising vibration generators distributed around the inner periphery of the mold and hydraulic jacks, preferably removable, distributed about such periphery neat the bottom of the mold and expandable downwardly to raise the mold. A set of three jacks and a set of three vibrators are preferred, attached respectively to the lower and upper parts of a two-part mold. The preferred form also has manually operable jacks and centering spindles for the mold and at its bottom edges a cylindrical ring movable to sealingly engage the surface therebelow, an annular platform proximate to the top of the lower part of the mold, and vibration generators comprising eccentric 30 F A li ti P 1 orelgn pp ca on nonty Data masses rotatable about vertical axis in different June 12, 1970 Netherlands ..700865l directions of rotation. 52 US. Cl. ..425/13 264/30 266/43 the the the mm is 51 Int. Cl .3 "F2711 1/16 timed raised free of of the vessel and [58] Field of Search m266/43; 264/30; 64/19 198. tered and levelled by the manual jacks, with the ring 249/142 144 425/11 13 14 60 H0 resting on the vessel bottom; the platform and upper part of the mold are assembled on the lower part, the centering spindles are retracted; the refractory mass is [56] References Cited slung into the space between the mold and the vessel walls; the hydraulic jacks are positioned at operative UNITED STATES PATENTS heights; the vibration generators and hydraulic acks are operated and then stopped; the manual jacks are l-lermgartner adjusted and the hydraulic jacks preferably removed 2 gllzlmkenhomw "425/110 and then the remaining mold parts. Concurrent and l 2 en Separate controls for the hydraulic jacks are Primary Examiner-Robert L. Spicer, .lr. preferably provlded' y- Hougmon 10 Claims, 5 Drawing Figures un 9 WI 5 ll 1 l' 'l I ll 8 l 13 12 G 20 l 4 APPARATUS FOR THE APPLICATION OF A REFRACTORY LINING TO THE INSIDE WALL OF METALLURGICAL VESSELS, AS WELL AS A MOULDING UNIT TO BE UTILIZED IN COMBINATION TIIEREWITII The invention relates to a method and an apparatus for the application of a refractory lining to the inside wall of metallurgical vessels, comprising a so called sand slinging device for the directional slinging of a refractory mass in granular form, and a moulding until which is adapted to be temporarily installed within the vessel, while leaving clear an annular space between said unit and the wall of said vessel. In addition thereto the invention relates to the moulding unit which forms part of said apparatus.-

The invention relates more particularly to the repairing of casting ladles for iron and steel works, though it is not limited thereto. In these works, casting ladles are generally used for the collection of 250 to 300 tons of crude steel. In order to be capable of withstanding the high temperatures of the molten steel, the inside wall of the vessels is often composed of several layers of refractory material. There is generally made a distinction between the so-called permanent lining and the socalled wearing lining. After the wearing lining has become worn out to an impermissible extent, the vessel is allowed to cool down and the entire wearing lining is removed to be replaced by a new lining. In order to cut the costs of the application of a new wearing lining, attempts have been made to realize a mechanization of said repairing. A particularly succesful form of mechanization of this repairing consists in that a wearing lining is applied with the aid of a so called sand slinging device, as is known from the art of manufacturing casting moulds for the foundry. In this process a sand slinging head, essentially consisting of an impeller rotating at high velocity, slings the moulding material between the permanent lining and a removable moulding unit or mould in the direction of the bottom of the vessel through a nozzle.

In the German magazine Stahl und Eisen 89 (1969, no. 16, 7 August), page 859, such a device has been described. Comparable structures are disclosed in other literature and are well-known in the art.

If the moulding unit or mould has been given a sim ple frustoconical shape and is hoisted up from the bottom of the vessel with the aid of a crane, after the slinging of sand has been finished, it appears in practice that serious damage to the wearing lining is unavoidable. Therefore, attempts have been made to embody the moulding unit such that this disadvantage may be avoided. In an embodiment previously used for said moulding unit, it is built up from several structural parts, which may be dismantled and removed individually.

It has appeared that with such an embodiment satisfactory results may be obtained, but that the dismantling of a mould of this type still requires a relatively considerable amount of labor and is still a relatively time-consuming procedure. For this reason, it is an object of the present invention to design an embodiment for the apparatus in which the moulding unit may be removed in a rapid and simple manner without the wearing lining being damaged to an impermissible extent. Owing to the present invention, such an embodiment of the moulding unit has indeed been obtained.

The present invention consists in that an apparatus as disclosed in the first paragraph of this specification is provided with vibrators on the inside of the mould and distributed about the inner periphery of said mould, while additional connecting means have been provided on the inside of the mould and distributed about the inner periphery thereof, in the zone close to the bottom edge of said mould, which connecting means serve to connect jacks thereto, which jacks are adapted to be energized hydraulically and to expand in a downward direction. This has .to do with the fact that it has appeared, somewhat contrary to the expectations of those skilled in the art, that it is possible with the aid of a suitable control program for the energizing of the vibrators, to loosen the mould under vibration from the slung mass to a sufficient extent to detach said mould by pressure with the aid of the jacks without damaging the layer of refractory material slung into the annular space. This is the more remarkable, since the slung mass is applied at a high momentum, thus having a very high compactness and hardness. On account of this it could have been expected that the additional compacting required for the detachment of said mass from the mould by vibration could not very well beachieved.

The mould together with the vibrators and the connecting means for the jacks constitutes a moulding unit which, as such, falls within the scope of the present invention as well.

It could be expected that the more vibrators are used producing a strong vibrating movement of the moulding unit and the more jacks are applied, jacking up said unit, the better the result of the present invention would be. However, it has appeared in practice that highly satisfactory results can be obtained if there are present three vibrators and connecting means for three hydraulic jacks.

In order to facilitate manipulating with the moulding unit during its positioning in and removal from the vessel, it has appeared to be advantageous according to the invention to have the mould comprise two annular mould parts which are adapted to be connected to one another, one above the other, the hydraulic jacks being connected to the lower one of such parts of the mould and the vibrators being connected to the upper one of said parts.

A conceivable embodiment is one in which the hydraulic jacks are rigidly connected to the moulding unit by means of the connecting means present. In this embodiment, the common supply system for feeding said jacks with the fluid may also be a part of the moulding unit. However, a more simple structure and a more simple manner of manoevering therewith can be realized if the hydraulic jacks are detachably connected to the bottom part of the moulding unit.

In order to obtain a wearing lining having a uniform thickness all over the periphery of the vessel, it is imperative to have means for the adjustment of the position of the moulding unit within the vessel.

It is herewith observed that the bottom of steel ladles, as well as of other metallurgical vessels, on which the moulding unit is supported, is generally not symmetrical with respect to the axis of the vessel, but rather slopes downwardly an eccentrically positioned tap hole. This arrangement makes it the more imperative to have adjusting means present in order to be able to adjust the position of the moulding unit both in a transverse direction and in various directions of rotation. A very suitable solution to this problem may be obtained according to the invention, if the moulding unit, preferably in the bottom portion, is provided with three manually operated jacks, which are adapted to expand in the downward direction, and with three screw spindles, which are adapted to be screwed outwardly through the wall of the mould, said jacks and spindles being uniformly space about the periphery of the moulding unit.

In this embodiment it is essential that the moulding unit is in contact with the bottom of the vessel, even after its position has been re-adjusted. This is to prevent the refractory mass from dropping on to the bottom of the vessel by passing underneath the bottom edge of the mould during the slinging of the mass into the slot-like space beyond the mould.

This may be achieved, for instance, by filling up the gap between the mould and the bottom of the vessel with a suitable filling material after the moulding unit has taken its final position. Said filling may consist of moulding sand or of separate undetached mould parts, if desired.

However, attempts have been made to find means which make the taking of such precautions by means of additional manual labor superfluous.

It has appeared that this object can be achieved according to the invention, if a substantially cylindrical annular body, which has a limited length of stroke and is freely movable in a mainly axial direction, is provided along the inside of the bottom edge of the mould. Said annular body will permit some adjustments to be made in the position of the mould, without the annular body and the bottom of the vessel losing contact with one another. By giving the annular member a height which is greater than the height of the maximum slot-like clearance to be expected to occur between the mould and the bottom of the vessel, it is achieved that under all conditions a satisfactory sealing will be ensured.

An additional device forming a part of the moulding unit consists of an annular platform which is detachably secured in the proximity of the top edge of the lower part of the mould. On this platform may be arranged hydraulic auxiliary equipment, which is needed for making the hydraulic jacks function. In addition to this, the final finishing to be carried out on the upper edge of the wearing lining may be carried out from said platform.

The mould may be made to vibrate by the vibrators in various manners, which may be effective to a greater or lesser extent. For this purpose, vibrators of several commercially available types may be utilized. It has appeared that satisfactory results may be obtained in a simple manner by utilizing vibrators which comprise eccentric masses rotatable in a plane extending transversely to the axis of the mould. As a result of this the mould is made to vibrate only in directions extending transversely to the axis of the mould with respect to the slung body of lining material. In essence, this form of vibration results in the body of said material being compressed to a further extent by the vibrating mould, in part, however, the mould is loosened with respect to the said body of the lining in the direction of rotation as well. Surprisingly, it has appeared that the best results can be obtained, if some of the vibrators utilized have a direction of rotation different from that of the others. If three vibrators are used, the direction of rotation of one of said vibrators will be different from that of the other two.

In utilizing the mould unit of the type described above the following operations have to be carried out successively according to the invention:

the bottom portion of the mould is placed in position and jacked up with the manually operated jacks until it is no longer in contact with the bottom of the vessel, and until the cylindrical ring is supported on said bottom, while it still has a possibility of movement in a vertical direction;

the bottom portion of the mould is centered with the aid of the screwed out screw spindles and is positioned accurately horizontally with its top edge with the aid of the manually operated jacks;

the platform and the top portion of the mould are mounted onto the bottom portion of the mould:

the screw spindles are screwed back and refractory mass is slung into the annular space between mould and vessel wall;

the hydraulic jacks are placed in position and expanded so far as to become operative on the moulding unit;

the vibrators are actuated and the hydraulic jacks are brought to a second higher pressure level;

the vibrators are stopped, the manually operated jacks are expanded to a further extent and the hydraulic jacks are removed,

the portions of the moulding unit are disconnected in inverted order and removed from the vessel.

As long as the hydraulic jacks are only adjusted to the initial operative level, there will not be any movement of the mould with respect to the wearing lining. Not until the vibrators have been actuated and the hydraulic jacks have been adjusted to a higher pressure level is it possible for the mould to be detached from said wearing lining. In that case the hydraulic system should function in such a way, however, that the hydraulic jacks will jack up the moulding unit over equal distances in the zone of the various points of application of these jacks. However, before the moulding unit is jacked up by the jacks it is only required to exert the same upward thrust on the moulding unit at the site of the various points of application of the jacks.

This may be realized according to the invention if an apparatus is utilized in which the hydraulic jacks are connected with a common liquid feed system allowing all the jacks together to be first of all expanded to operative level, after which the jacks are simultaneously adjusted to a second, higher pressure level by individual but uniform additional supplies of the hydraulic liquid.

The invention will now be explained in more detail with reference to the enclosed drawings, giving by way of example a preferred embodiment of an apparatus according to the invention.

FIG. 1 shows a vertical sectional view of a steel ladle with a moulding unit according to the invention.

FIG. 2 shows a diagrammatic view of a part of the hydraulic system.

FIG. 3 shows the detail III of FIG. 1 on an enlarged scale.

FIG. 4 and 5 show other details of FIG. I, also on an enlarged scale.

In FIG. 1, the reference numeral 1 indicates the steel jacket of a steel ladle. The bottom of the vessel has been provided with a permanent refractory brick lining 2 and a refractory wearing lining 3. The permanent lining 4 is applied to the wall of the vessel.

The moulding unit is essentially formed by a top mold portion 5 and a bottom mold portion 6. The portions 5 and 6 are connected with one another by means of two annular flanges 7 and 8 with the aid of keys or the like.

Furthermore, the portion 5 and 6 of the mould are rendered rigid to deformation by the rings 9, 10, I1 and 12. Ring 12 also serves as a support for three legs 13 of an annular platform 14. The platform 14 is bounded at the inside by the upright balustrade 15 with handrail on top. A ring-shaped member 16 is suspended within the mould, at the bottom thereof, by means of three bolts 17 which extend through the ring 11.

In FIG. 3 this detail is shown on an enlarged scale. With this it is achieved that the moulding unit can be adjusted in a vertical direction and can be slightly tilted, without spoiling the sealing between the moulding unit and the permanent lining 3 of the bottom of the vessel.

Three vibrators (vibration generators) 19 are connected to the rings 9 and 7 of the top portion of the mould, said vibrators being uniformly spaced about the periphery of the mould. Said vibrators 19 comprise electric motors with the axis arranged in a vertical direction, which electric motors support on their axis an eccentric mass. Said motors have a power of 0.55 kW and a speed of 1450 r.p.m. The unbalance force amounts to approximately 1.7 tons. Two out of three vibrators rotate clockwise, while the third one rotates in an anti-clockwise direction or the reverse, as seen from above.

Three screw spindles 20, spaced uniformly about the periphery of the mould, are connected to the bottom portion 6 of the mould, which screw spindles are adapted to be screwed out through the mould wall to the outside by hand. With the aid of said screw spindles, it is possible to bring the mould in line with respect to the permanent lining 4 of the wall of the vessel. At a level with the screw spindles 20, three manually operated jacks 21 are connected with the bottom portion 6 of the mould, said jacks being shown in greater detail in FIG. 5. With the aid of said manually operated jacks, the moulding unit can be adjusted in the correct horizontal position. In the proximity of the manually operated jacks 21 there are three hydraulic jacks 22 which are adapted to be connected to the moulding unit. In FIG. 4 is shown in what way said hydraulic jacks 22 can be connected to the portion 6 of the mould.

At the top of the portion 5 of the mould there is secured a concentric ring 23, two guide rollers 28 and 29 rollers along said ring. Said rollers 28 and 29 are attached to the sand slinging device 24 by means of a frame 27, which slinging device is adapted to sling moulding refractory material as a jet 26 through a nozzle 25 into the ring-shaped space between the mould and the permanent lining 4 of the casting vessel. There is a high speed rotating impeller (not shown) with a horizontal axis perpendicular to the plane of drawing of FIG. 1 within the casing indicated by 24, said impeller being driven by an electric motor (not shown) and slinging sand or refractory granular material, fed from one side into said casing, into and through nozzle 25. With the aid of the rollers 28 and 29 and the concentric ring 23 a satisfactory positioning of the slinging device 24 with respect to the space between the mould and the permanent lining is ensured under all conditions. A more detailed description of the slinging device 24 is superfluous, since this is of a type generally known and published in the art.

After the moulding unit has been placed in position on the bottom of the vessel, its position is accurately centralized with respect to the ladle with the aid of the manually operated jacks 21 and the screw spindles 20.

During said process a large gap will appear between the mould and the bottom of the vessel, resulting from the fact that said bottom slopes eccentrically towards the eccentrically positioned taphole (not shown in the drawing). The screw spindles 20 are thereupon screwed back and the slinging device 24 is operated. The vessel is then rotated with respect to the slinging device. In this instance, it is not of importance whether the vessel rotates and the slinging device is kept stationary or the reverse.

After the annular space is completely filled refractory moulding material, the hydraulic jacks 22 are placed in position and adjusted to the initial operative height. During this procedure the mould is still stationary, but the weight of the moulding unit itself is taken up already by these jacks. Simultaneously, the vibrators 19 are operated and the hydraulic jacks 22 are adjusted to a higher oil pressure level. Thereupon the moulding unit is jacked up to a height which suffices to detach the moulding unit from the conically-shaped permanent lining. After the manually operated jacks 21 have subsequently been turned down to a further extent and the oil pressure has been removed from the hydraulic jacks, the moulding unit can be dismantled. To this end, first of all the top portion of the mould together with the platform is removed, whereupon finally the bottom portion of the mould with the accessories thereof are hoisted up from the bottom of and out of the vessel.

FIG. 2 shows a detail diagram of connections of th hydraulic system. The oil which is fed to the jacks 22 originates from the pump 30. The pump pressure is checked by means of a manometer 31, while an excess of the oil under excess pressure is allowed to escape through overflow valve 32. Through the duct 33 the oil is fed to the switch valve 34 and from there it is passed to the lower side of the plungers of the jacks 22 through duct 43 and through the opened valves 44, 45, 46, during the phase wherein the initial operative pressure is exerted. In addition thereto, the oil will simultaneously be passed to'the spaces on the right-hand side of the plunger assembly in the equalizing system 38 through ducts 40, 41 and 42. Thereby the plunger assembly 39 will perform a movement to the left.

Now if the moulding unit has to be jacked up, the overflow valve 32 will be re-adjusted to a higher value, the valves 44, 45 and 46 will be closed and the switch valve 34 will be switched to the other end position. The oil pressure will thereupon be transferred to the spaces the equalizing system 38, causing said plungers to perform a synchronous movement to the right. Accordingly, oil will be passed under pressure through the ducts 40, 41 and 42 below the plungers of the jacks 22 in metered, uniform quantities. As a result thereof, said jacks will be thrust upwards over mutually equal distances. Simultaneously herewith, the vibrators 19 are actuated with the result that the slung moulding material is compressed which, in its turn, results in the mould becoming detached from said moulding material forming the new wearing lining.

FIG. 4 shows in more detail in what manner the hydraulic jack 22 may be connected to the bottom portion 6 of the mould. For this purpose, the end of the jack is provided with a screw threaded part 51, onto which a nut with a collar 52 can be screwed. Said nut is in contact with the forked support 54, while the casing of the jack is also aligned by the forked support 53. Said jack will now, with the bottom of the casing of the jack(at the upper end)be.in contact with the bracket 47. Retaining rods 56 and 57 are rotatable about a rotary shaft 55 (outside the plane of the drawing), which rods are thus retaining the jack. The piston rod 48 is at its end provided with a spherical head 49, which is retained in a shoe 50. On account of this, the shoe can take any position with respect to the jack which is necessary to adjust itself to the slope of the permanent lining 3 of the bottom of the vessel.

In FIG. is shown in more detail in what manner the manually operated jack 21 is connected to the bottom portion 6 of the mould. To this end, this jack is adapted to be screwed with its screw-threaded part 58 into a screw threaded tube 59 which is secured to portion 6 of the mould by means of a hub and two supports 60 and 61. In a manner similar to the manner described in FIG. 4 the manually operated jack 21 is retained in a shoe 65 which is adapted to adjust itself to the slope of the bottom of the vessel. By means of spokes which may be inserted through holes 63 in the shaft of the jack 21, said jack may be turned and thus be moved in a vertical direction.

' We claim:

1. Apparatus for the application ofa refractory lining to the inside wall of metallurgical vessels, comprising a so-called sand slinging device for the directional slinging of a refractory mass in granular form, and a moulding unit, which is adapted to be temporarily installed within the vessel, while leaving clear an annular space between the mould of said unit and the wall of said vessel, characterized in that on the side of the mould, distributed about the inner periphery thereof, there are provided vibration generators and that on the inside and distributed about the inner periphery of the mould, in the proximity of the bottom edge thereof, there are provided connecting means for the connection of jacks which are adapted to be energized hydraulically and are expansible in a downward direction.

2. A moulding unit as a part of the apparatus according to claim 1. 1

3. The moulding unit according to claim 2, characterized in that there are present three vibration generators and connecting means for three hydraulic jacks.

4. The moulding unit according to claim 2, characterized in that the mould comprises two annular mould parts, which are adapted to be connected together, one

above the other, the hydraulic jacks being connected to the lower one of such parts of the mould and the vibration generators being attached to the upper one of such parts of said mould.

5. The moulding unit according to claim 2, characterized in that the hydraulic jacks are detachably fastened to the said lower part of the mould.

6. The moulding unit according to claim 4, characterized in that the mould, preferably in the said lower part, and distributed about the periphery thereof, comprises three manually operated jacks which are adapted to be expanded in downward direction and three screw spindles which are adapted to be screwed out through the wall of the mould to the outside.

7. The moulding unit according to claim 2, characterized in that alongside the inside wall of the bottom edge of the mould there is a cylindrically-shaped ring which has a limited length of stroke of movement and is freely movable in a mainly axial direction.

8. The moulding unit according to claim 4, characterized in that an annular platform is detachably arranged in the proximity of the top edge of the said lower part of the mould.

9. The moulding unit according to claim 2, characterized in that the vibration generators, in a plane transverse to the axis of the mould, comprise rotatable eccentric masses, and that part of said vibration generators are adapted to rotate in a different direction of rotation than the other generators.

10. The apparatus according claim 1, characterized in that the hydraulic jacks are connected to a common feed system by means of which first of all all said jacks together can be adjusted to an operative level, whereupon the jacks are simultaneously adjusted to a second, higher pressure level by individual, but uniform additional quantities of liquid supplied. 

1. Apparatus for the application of a refractory lining to the inside wall of metallurgical vessels, comprising a so-called sand slinging device for the directional slinging of a refractory mass in granular form, and a moulding unit, which is adapted to be temporarily installed within the vessel, while leaving clear an annular space between the mould of said unit and the wall of said vessel, characterized in that on the side of the mould, distributed about the inner periphery thereof, there are provided vibration generators and that on the inside and distributed about the inner periphery of the mould, in the proximity of the bottom edge thereof, there are provided connecting means for the connection of jacks which are adapted to be energized hydraulically and are expansible in a downward direction.
 2. A moulding unit as a part of the apparatus according to claim
 1. 3. The moulding unit according to claim 2, characterized in that there are present three vibration generators and connecting means for three hydraulic jacks.
 4. The moulding unit according to claim 2, characterized in that the mould comprises two annular mould parts, which are adapted to be connected together, one above the other, the hydraulic jacks being connected to the lower one of such parts of the mould and the vibration generators being attached to the upper one of such parts of said mould.
 5. The moulding unit according to claim 2, characterized in that the hydraulic jacks are detachably fastened to the said lower part of the mould.
 6. The moulding unit according to claim 4, characterized in that the mould, preferably in the said lower part, and distributed about the periphery thereof, comprises three manually operated jacks which are adapted to be expanded in downward direction and three screw spindles which are adapted to be screwed out through the wall of the mould to the outside.
 7. The moulding unit according to claim 2, characterized in that alongside the inside wall of the bottom edge of the mould there is a cylindrically-shaped ring which has a limited length of stroke of movement and is freely movable in a mainly axial direction.
 8. The moulding unit according to claim 4, characterized in that an annular platform is detachably arranged in the proximity of the top edge of the said lower part of the mould.
 9. The moulding unit according to claim 2, characterized in that the vibration generators, in a plane transverse to the axis of the mould, comprise rotatable eccentric masses, and that part of said vibration generators are adapted to rotate in a different direction of rotation than the other generators. 